/*
Blink
Turns on an LED on for two second, then off for two second, repeatedly.
This example code is in the public domain.
*/
void setup() {
// initialize the digital pin as an output.
// Pin 13 has an LED connected on most Arduino boards:
  pinMode(13, OUTPUT);
}
void loop() {
  digitalWrite(13, HIGH); // set the LED on
  delay(2000); // wait for a second
  digitalWrite(13, LOW); // set the LED off
  delay(2000); // wait for a second
}
